X-Git-Url: http://git.localhorst.tv/?a=blobdiff_plain;f=src%2Fcreature%2Fcreature.cpp;h=b95b531a13097041c2b7e835d4d69483f3798446;hb=b4deadd9f4e399207e2530ea39a447c0d9d260a3;hp=043aed7353cd66d4c2d6fbfff8eaf8e830f25031;hpb=3b0a4ba59825b2d6a47e9d997736742edf55240c;p=blobs.git

diff --git a/src/creature/creature.cpp b/src/creature/creature.cpp
index 043aed7..b95b531 100644
--- a/src/creature/creature.cpp
+++ b/src/creature/creature.cpp
@@ -1,19 +1,25 @@
+#include "Composition.hpp"
 #include "Creature.hpp"
+#include "Genome.hpp"
+#include "Memory.hpp"
+#include "NameGenerator.hpp"
 #include "Situation.hpp"
 #include "Steering.hpp"
 
+#include "BlobBackgroundTask.hpp"
 #include "Goal.hpp"
-#include "InhaleNeed.hpp"
-#include "IngestNeed.hpp"
-#include "Need.hpp"
+#include "IdleGoal.hpp"
 #include "../app/Assets.hpp"
+#include "../math/const.hpp"
 #include "../world/Body.hpp"
 #include "../world/Planet.hpp"
 #include "../world/Simulation.hpp"
 #include "../world/TileType.hpp"
 
 #include <algorithm>
+#include <sstream>
 #include <glm/gtx/transform.hpp>
+#include <glm/gtx/vector_angle.hpp>
 
 #include <iostream>
 #include <glm/gtx/io.hpp>
@@ -22,28 +28,224 @@
 namespace blobs {
 namespace creature {
 
+Composition::Composition()
+: components() {
+}
+
+Composition::~Composition() {
+}
+
+namespace {
+bool CompositionCompare(const Composition::Component &a, const Composition::Component &b) {
+	return b.value < a.value;
+}
+}
+
+void Composition::Add(int res, double amount) {
+	bool found = false;
+	for (auto &c : components) {
+		if (c.resource == res) {
+			c.value += amount;
+			found = true;
+			break;
+		}
+	}
+	if (!found) {
+		components.emplace_back(res, amount);
+	}
+	std::sort(components.begin(), components.end(), CompositionCompare);
+}
+
+bool Composition::Has(int res) const noexcept {
+	for (auto &c : components) {
+		if (c.resource == res) {
+			return true;
+		}
+	}
+	return false;
+}
+
+double Composition::Get(int res) const noexcept {
+	for (auto &c : components) {
+		if (c.resource == res) {
+			return c.value;
+		}
+	}
+	return 0.0;
+}
+
+
 Creature::Creature(world::Simulation &sim)
 : sim(sim)
 , name()
+, genome()
+, properties()
+, composition()
+, base_color(1.0)
+, highlight_color(0.0, 0.0, 0.0, 1.0)
+, mass(1.0)
 , size(1.0)
-, health(1.0)
-, needs()
+, birth(sim.Time())
+, on_death()
+, removable(false)
+, stats()
+, memory(*this)
+, bg_task()
 , goals()
 , situation()
-, steering()
-, vel(0.0)
+, steering(*this)
 , vao() {
+	// all creatures avoid each other for now
+	steering.Separate(0.1, 1.5);
 }
 
 Creature::~Creature() {
 }
 
-void Creature::Hurt(double dt) noexcept {
-	health = std::max(0.0, health - dt);
+void Creature::AddMass(int res, double amount) {
+	composition.Add(res, amount);
+	double mass = 0.0;
+	double nonsolid = 0.0;
+	double volume = 0.0;
+	for (const auto &c : composition) {
+		mass += c.value;
+		volume += c.value / sim.Assets().data.resources[c.resource].density;
+		if (sim.Assets().data.resources[c.resource].state != world::Resource::SOLID) {
+			nonsolid += c.value;
+		}
+	}
+	Mass(mass);
+	Size(std::cbrt(volume));
+	highlight_color.a = nonsolid / mass;
+}
+
+void Creature::HighlightColor(const glm::dvec3 &c) noexcept {
+	highlight_color = glm::dvec4(c, highlight_color.a);
+}
+
+void Creature::Ingest(int res, double amount) noexcept {
+	// TODO: check foreign materials
+	// 10% stays in body
+	AddMass(res, amount * 0.1);
+}
+
+void Creature::Hurt(double amount) noexcept {
+	stats.Damage().Add(amount);
+	if (stats.Damage().Full()) {
+		std::cout << "[" << int(sim.Time()) << "s] " << name << " ";
+		if (stats.Exhaustion().Full()) {
+			std::cout << "died of exhaustion";
+		} else if (stats.Breath().Full()) {
+			std::cout << "suffocated";
+		} else if (stats.Thirst().Full()) {
+			std::cout << "died of thirst";
+		} else if (stats.Hunger().Full()) {
+			std::cout << "starved to death";
+		} else {
+			std::cout << "succumed to wounds";
+		}
+		std::cout << " at an age of ";
+		{
+			int age = int(Age());
+			if (age >= 3600) {
+				std::cout << (age / 3600) << "h ";
+				age %= 3600;
+			}
+			if (age >= 60) {
+				std::cout << (age / 60) << "m ";
+				age %= 60;
+			}
+			std::cout << age << 's';
+		}
+		std::cout << " (" << int(Age() / properties.Lifetime() * 100)
+			<< "% of life expectancy of ";
+		{
+			int lt = int(properties.Lifetime());
+			if (lt >= 3600) {
+				std::cout << (lt / 3600) << "h ";
+				lt %= 3600;
+			}
+			if (lt >= 60) {
+				std::cout << (lt / 60) << "m ";
+				lt %= 60;
+			}
+			std::cout << lt << 's';
+		}
+		std::cout << ")" << std::endl;
+		Die();
+	}
+}
+
+void Creature::Die() noexcept {
+	goals.clear();
+	steering.Halt();
+	if (on_death) {
+		on_death(*this);
+	}
+	Remove();
+}
+
+double Creature::Age() const noexcept {
+	return sim.Time() - birth;
+}
+
+double Creature::AgeFactor(double peak) const noexcept {
+	// shifted inverse hermite, y = 1 - (3t² - 2t³) with t = normalized age - peak
+	// goes negative below -0.5 and starts to rise again above 1.0
+	double t = glm::clamp((Age() / properties.Lifetime()) - peak, -0.5, 1.0);
+	return 1.0 - (3.0 * t * t) + (2.0 * t * t * t);
+}
+
+double Creature::ExhaustionFactor() const noexcept {
+	return 1.0 - (glm::smoothstep(0.5, 1.0, stats.Exhaustion().value) * 0.5);
+}
+
+double Creature::FatigueFactor() const noexcept {
+	return 1.0 - (glm::smoothstep(0.5, 1.0, stats.Fatigue().value) * 0.5);
+}
+
+double Creature::Strength() const noexcept {
+	// TODO: replace all age factors with actual growth and decay
+	return properties.Strength() * ExhaustionFactor() * AgeFactor(0.25);
+}
+
+double Creature::Stamina() const noexcept {
+	return properties.Stamina() * ExhaustionFactor() * AgeFactor(0.25);
+}
+
+double Creature::Dexerty() const noexcept {
+	return properties.Dexerty() * ExhaustionFactor() * AgeFactor(0.25);
+}
+
+double Creature::Intelligence() const noexcept {
+	return properties.Intelligence() * FatigueFactor() * AgeFactor(0.25);
+}
+
+double Creature::Lifetime() const noexcept {
+	return properties.Lifetime();
+}
+
+double Creature::Fertility() const noexcept {
+	return properties.Fertility() * AgeFactor(0.25);
+}
+
+double Creature::Mutability() const noexcept {
+	return properties.Mutability();
+}
+
+double Creature::OffspringMass() const noexcept {
+	return properties.OffspringMass();
+}
+
+double Creature::OffspringChance() const noexcept {
+	return AgeFactor(0.25) * properties.Fertility() * (1.0 / 3600.0);
+}
+
+double Creature::MutateChance() const noexcept {
+	return GetProperties().Mutability() * (1.0 / 3600.0);
 }
 
 void Creature::AddGoal(std::unique_ptr<Goal> &&g) {
-	std::cout << "new goal: " << g->Describe() << std::endl;
 	g->Enable();
 	goals.emplace_back(std::move(g));
 }
@@ -57,38 +259,111 @@ bool GoalCompare(const std::unique_ptr<Goal> &a, const std::unique_ptr<Goal> &b)
 }
 
 void Creature::Tick(double dt) {
-	// TODO: better integration method
-	glm::dvec3 acc(steering.Acceleration(*this));
-	situation.Move(vel * dt);
-	vel += acc * dt;
+	TickState(dt);
+	TickStats(dt);
+	TickBrain(dt);
+}
 
-	for (auto &need : needs) {
-		need->Tick(dt);
+void Creature::TickState(double dt) {
+	steering.MaxSpeed(Dexerty());
+	steering.MaxForce(Strength());
+	Situation::State state(situation.GetState());
+	Situation::Derivative a(Step(Situation::Derivative(), 0.0));
+	Situation::Derivative b(Step(a, dt * 0.5));
+	Situation::Derivative c(Step(b, dt * 0.5));
+	Situation::Derivative d(Step(c, dt));
+	Situation::Derivative f(
+		(1.0 / 6.0) * (a.vel + 2.0 * (b.vel + c.vel) + d.vel),
+		(1.0 / 6.0) * (a.acc + 2.0 * (b.acc + c.acc) + d.acc)
+	);
+	state.pos += f.vel * dt;
+	state.vel += f.acc * dt;
+	situation.EnforceConstraints(state);
+	if (length2(state.vel) > 0.000001) {
+		glm::dvec3 nvel(normalize(state.vel));
+		double ang = angle(nvel, state.dir);
+		double turn_rate = PI * 0.75 * dt;
+		if (ang < turn_rate) {
+			state.dir = normalize(state.vel);
+		} else if (std::abs(ang - PI) < 0.001) {
+			state.dir = rotate(state.dir, turn_rate, world::Planet::SurfaceNormal(situation.Surface()));
+		} else {
+			state.dir = rotate(state.dir, turn_rate, normalize(cross(state.dir, nvel)));
+		}
 	}
-	for (auto &goal : goals) {
-		goal->Tick(dt);
+	situation.SetState(state);
+	stats.Exhaustion().Add(length(f.acc) * Mass() / Stamina() * 0.5 * dt);
+}
+
+Situation::Derivative Creature::Step(const Situation::Derivative &ds, double dt) const noexcept {
+	Situation::State s = situation.GetState();
+	s.pos += ds.vel * dt;
+	s.vel += ds.acc * dt;
+	glm::dvec3 force(steering.Force(s));
+	// gravity = antinormal * mass * Gm / r²
+	double elevation = s.pos[(situation.Surface() + 2) % 3];
+	glm::dvec3 normal(world::Planet::SurfaceNormal(situation.Surface()));
+	force += glm::dvec3(
+		-normal
+		* Mass() * situation.GetPlanet().GravitationalParameter()
+		/ (elevation * elevation));
+	// if net force is applied and in contact with surface
+	if (!allzero(force) && std::abs(std::abs(elevation) - situation.GetPlanet().Radius()) < 0.001) {
+		// apply friction = -|normal force| * tangential force * coefficient
+		glm::dvec3 fn(normal * dot(force, normal));
+		glm::dvec3 ft(force - fn);
+		double u = 0.4;
+		glm::dvec3 friction(-length(fn) * ft * u);
+		force += friction;
 	}
-	// do background stuff
-	for (auto &need : needs) {
-		need->ApplyEffect(*this, dt);
+	return {
+		s.vel,
+		force / Mass()
+	};
+}
+
+void Creature::TickStats(double dt) {
+	for (auto &s : stats.stat) {
+		s.Add(s.gain * dt);
+	}
+	stats.Breath().Add(stats.Breath().gain * stats.Exhaustion().value * dt);
+	// TODO: damage values depending on properties
+	if (stats.Breath().Full()) {
+		constexpr double dps = 1.0 / 4.0;
+		Hurt(dps * dt);
 	}
+	if (stats.Thirst().Full()) {
+		constexpr double dps = 1.0 / 32.0;
+		Hurt(dps * dt);
+	}
+	if (stats.Hunger().Full()) {
+		constexpr double dps = 1.0 / 128.0;
+		Hurt(dps * dt);
+	}
+	if (!situation.Moving()) {
+		// double exhaustion recovery when standing still
+		stats.Exhaustion().Add(stats.Exhaustion().gain * dt);
+	}
+}
+
+void Creature::TickBrain(double dt) {
+	bg_task->Tick(dt);
+	bg_task->Action();
+	memory.Tick(dt);
+	// do background stuff
 	if (goals.empty()) {
 		return;
 	}
+	for (auto &goal : goals) {
+		goal->Tick(dt);
+	}
 	// if active goal can be interrupted, check priorities
 	if (goals.size() > 1 && goals[0]->Interruptible()) {
-		Goal *old_top = &*goals[0];
 		std::sort(goals.begin(), goals.end(), GoalCompare);
-		Goal *new_top = &*goals[0];
-		if (new_top != old_top) {
-			std::cout << "changing goal from " << old_top->Describe()
-				<< " to " << new_top->Describe() << std::endl;
-		}
 	}
 	goals[0]->Action();
 	for (auto goal = goals.begin(); goal != goals.end();) {
 		if ((*goal)->Complete()) {
-			std::cout << "complete goal: " << (*goal)->Describe() << std::endl;
 			goals.erase(goal);
 		} else {
 			++goal;
@@ -96,11 +371,22 @@ void Creature::Tick(double dt) {
 	}
 }
 
-glm::dmat4 Creature::LocalTransform() noexcept {
-	// TODO: surface transform
+math::AABB Creature::CollisionBox() const noexcept {
+	return { glm::dvec3(size * -0.5), glm::dvec3(size * 0.5) };
+}
+
+glm::dmat4 Creature::CollisionTransform() const noexcept {
 	const double half_size = size * 0.5;
 	const glm::dvec3 &pos = situation.Position();
+	const glm::dmat3 srf(world::Planet::SurfaceOrientation(situation.Surface()));
 	return glm::translate(glm::dvec3(pos.x, pos.y, pos.z + half_size))
+		* glm::rotate(glm::orientedAngle(-srf[2], situation.Heading(), srf[1]), srf[1])
+		* glm::dmat4(srf);
+}
+
+glm::dmat4 Creature::LocalTransform() noexcept {
+	const double half_size = size * 0.5;
+	return CollisionTransform()
 		* glm::scale(glm::dvec3(half_size, half_size, half_size));
 }
 
@@ -186,16 +472,16 @@ void Creature::BuildVAO() {
 	vao.Unbind();
 }
 
-void Creature::Draw(app::Assets &assets, graphics::Viewport &viewport) {
+void Creature::Draw(graphics::Viewport &viewport) {
 	vao.Bind();
 	vao.DrawTriangles(6 * 6);
 }
 
 
-void Spawn(Creature &c, world::Planet &p, app::Assets &assets) {
+void Spawn(Creature &c, world::Planet &p) {
 	p.AddCreature(&c);
 	c.GetSituation().SetPlanetSurface(p, 0, p.TileCenter(0, p.SideLength() / 2, p.SideLength() / 2));
-	c.Size(0.5);
+	c.GetSituation().Heading(-world::Planet::SurfaceOrientation(0)[2]);
 
 	// probe surrounding area for common resources
 	int start = p.SideLength() / 2 - 2;
@@ -203,7 +489,7 @@ void Spawn(Creature &c, world::Planet &p, app::Assets &assets) {
 	std::map<int, double> yields;
 	for (int y = start; y < end; ++y) {
 		for (int x = start; x < end; ++x) {
-			const world::TileType &t = assets.data.tile_types[p.TileAt(0, x, y).type];
+			const world::TileType &t = p.TypeAt(0, x, y);
 			for (auto yield : t.resources) {
 				yields[yield.resource] += yield.ubiquity;
 			}
@@ -212,49 +498,188 @@ void Spawn(Creature &c, world::Planet &p, app::Assets &assets) {
 	int liquid = -1;
 	int solid = -1;
 	for (auto e : yields) {
-		if (assets.data.resources[e.first].state == world::Resource::LIQUID) {
+		if (c.GetSimulation().Resources()[e.first].state == world::Resource::LIQUID) {
 			if (liquid < 0 || e.second > yields[liquid]) {
 				liquid = e.first;
 			}
-		} else if (assets.data.resources[e.first].state == world::Resource::SOLID) {
+		} else if (c.GetSimulation().Resources()[e.first].state == world::Resource::SOLID) {
 			if (solid < 0 || e.second > yields[solid]) {
 				solid = e.first;
 			}
 		}
 	}
 
+	Genome genome;
+	genome.properties.Strength() = { 2.0, 0.1 };
+	genome.properties.Stamina() = { 2.0, 0.1 };
+	genome.properties.Dexerty() = { 2.0, 0.1 };
+	genome.properties.Intelligence() = { 1.0, 0.1 };
+	genome.properties.Lifetime() = { 480.0, 60.0 };
+	genome.properties.Fertility() = { 0.5, 0.03 };
+	genome.properties.Mutability() = { 1.0, 0.1 };
+	genome.properties.OffspringMass() = { 0.3, 0.02 };
+
+	glm::dvec3 color_avg(0.0);
+	double color_divisor = 0.0;
+
 	if (p.HasAtmosphere()) {
-		std::cout << "require breathing " << assets.data.resources[p.Atmosphere()].label << std::endl;
-		std::unique_ptr<Need> need(new InhaleNeed(p.Atmosphere(), 0.5, 0.1));
-		need->name = assets.data.resources[p.Atmosphere()].label;
-		need->gain = 0.2;
-		need->inconvenient = 0.4;
-		need->critical = 0.95;
-		c.AddNeed(std::move(need));
+		c.AddMass(p.Atmosphere(), 0.01);
+		color_avg += c.GetSimulation().Resources()[p.Atmosphere()].base_color * 0.1;
+		color_divisor += 0.1;
 	}
 	if (liquid > -1) {
-		std::cout << "require drinking " << assets.data.resources[liquid].label << std::endl;
-		std::unique_ptr<Need> need(new IngestNeed(liquid, 0.2, 0.01));
-		need->name = assets.data.resources[liquid].label;
-		need->gain = 0.02;
-		need->inconvenient = 0.6;
-		need->critical = 0.95;
-		c.AddNeed(std::move(need));
+		c.AddMass(liquid, 0.3);
+		color_avg += c.GetSimulation().Resources()[liquid].base_color * 0.5;
+		color_divisor += 0.5;
 	}
 	if (solid > -1) {
-		std::cout << "require eating " << assets.data.resources[solid].label << std::endl;
-		std::unique_ptr<Need> need(new IngestNeed(solid, 0.1, 0.001));
-		need->name = assets.data.resources[solid].label;
-		need->gain = 0.017;
-		need->inconvenient = 0.6;
-		need->critical = 0.95;
-		c.AddNeed(std::move(need));
+		c.AddMass(solid, 0.1);
+		color_avg += c.GetSimulation().Resources()[solid].base_color;
+		color_divisor += 1.0;
+	}
+
+	if (color_divisor > 0.001) {
+		color_avg /= color_divisor;
+	}
+	glm::dvec3 hsl = rgb2hsl(color_avg);
+	genome.base_hue = { hsl.x, 0.01 };
+	genome.base_saturation = { hsl.y, 0.01 };
+	genome.base_lightness = { hsl.z, 0.01 };
+
+	genome.Configure(c);
+}
+
+void Genome::Configure(Creature &c) const {
+	c.GetGenome() = *this;
+
+	math::GaloisLFSR &random = c.GetSimulation().Assets().random;
+
+	c.GetProperties() = Instantiate(properties, random);
+
+	// TODO: derive stats from properties
+	c.GetStats().Damage().gain = (-1.0 / 100.0);
+	c.GetStats().Breath().gain = (1.0 / 5.0);
+	c.GetStats().Thirst().gain = (1.0 / 60.0);
+	c.GetStats().Hunger().gain = (1.0 / 200.0);
+	c.GetStats().Exhaustion().gain = (-1.0 / 100.0);
+	c.GetStats().Fatigue().gain = (-1.0 / 100.0);
+	c.GetStats().Boredom().gain = (1.0 / 300.0);
+
+	glm::dvec3 base_color(
+		std::fmod(base_hue.FakeNormal(random.SNorm()) + 1.0, 1.0),
+		glm::clamp(base_saturation.FakeNormal(random.SNorm()), 0.0, 1.0),
+		glm::clamp(base_lightness.FakeNormal(random.SNorm()), 0.0, 1.0)
+	);
+	glm::dvec3 highlight_color(
+		std::fmod(base_color.x + 0.5, 1.0),
+		1.0 - base_color.y,
+		1.0 - base_color.z
+	);
+	c.BaseColor(hsl2rgb(base_color));
+	c.HighlightColor(hsl2rgb(highlight_color));
+	c.SetBackgroundTask(std::unique_ptr<Goal>(new BlobBackgroundTask(c)));
+	c.AddGoal(std::unique_ptr<Goal>(new IdleGoal(c)));
+}
+
+
+void Split(Creature &c) {
+	Creature *a = new Creature(c.GetSimulation());
+	const Situation &s = c.GetSituation();
+	a->Name(c.GetSimulation().Assets().name.Sequential());
+	c.GetGenome().Configure(*a);
+	for (const auto &cmp : c.GetComposition()) {
+		a->AddMass(cmp.resource, cmp.value * 0.5);
+	}
+	s.GetPlanet().AddCreature(a);
+	// TODO: duplicate situation somehow
+	a->GetSituation().SetPlanetSurface(
+		s.GetPlanet(), s.Surface(),
+		s.Position() + glm::dvec3(0.0, 0.55 * a->Size(), 0.0));
+	a->BuildVAO();
+	std::cout << "[" << int(c.GetSimulation().Time()) << "s] "
+		<< a->Name() << " was born" << std::endl;
+
+	Creature *b = new Creature(c.GetSimulation());
+	b->Name(c.GetSimulation().Assets().name.Sequential());
+	c.GetGenome().Configure(*b);
+	for (const auto &cmp : c.GetComposition()) {
+		b->AddMass(cmp.resource, cmp.value * 0.5);
+	}
+	s.GetPlanet().AddCreature(b);
+	b->GetSituation().SetPlanetSurface(
+		s.GetPlanet(), s.Surface(),
+		s.Position() - glm::dvec3(0.0, 0.55 * b->Size(), 0.0));
+	b->BuildVAO();
+	std::cout << "[" << int(c.GetSimulation().Time()) << "s] "
+		<< b->Name() << " was born" << std::endl;
+
+	c.Die();
+}
+
+
+Memory::Memory(Creature &c)
+: c(c) {
+}
+
+Memory::~Memory() {
+}
+
+void Memory::Tick(double dt) {
+	Situation &s = c.GetSituation();
+	if (s.OnTile()) {
+		TrackStay({ &s.GetPlanet(), s.Surface(), s.SurfacePosition() }, dt);
+	}
+}
+
+void Memory::TrackStay(const Location &l, double t) {
+	const world::TileType &type = l.planet->TypeAt(l.surface, l.coords.x, l.coords.y);
+	auto entry = known_types.find(type.id);
+	if (entry != known_types.end()) {
+		if (c.GetSimulation().Time() - entry->second.last_been > c.GetProperties().Lifetime() * 0.1) {
+			// "it's been ages"
+			if (entry->second.time_spent > c.Age() * 0.25) {
+				// the place is very familiar
+				c.GetStats().Boredom().Add(-0.2);
+			} else {
+				// infrequent stays
+				c.GetStats().Boredom().Add(-0.1);
+			}
+		}
+		entry->second.last_been = c.GetSimulation().Time();
+		entry->second.last_loc = l;
+		entry->second.time_spent += t;
+	} else {
+		known_types.emplace(type.id, Stay{
+			c.GetSimulation().Time(),
+			l,
+			c.GetSimulation().Time(),
+			l,
+			t
+		});
+		// completely new place, interesting
+		// TODO: scale by personality trait
+		c.GetStats().Boredom().Add(-0.25);
 	}
 }
 
+
+NameGenerator::NameGenerator()
+: counter(0) {
+}
+
+NameGenerator::~NameGenerator() {
+}
+
+std::string NameGenerator::Sequential() {
+	std::stringstream ss;
+	ss << "Blob " << ++counter;
+	return ss.str();
+}
+
+
 Situation::Situation()
 : planet(nullptr)
-, position(0.0)
+, state(glm::dvec3(0.0), glm::dvec3(0.0))
 , surface(0)
 , type(LOST) {
 }
@@ -270,26 +695,49 @@ bool Situation::OnSurface() const noexcept {
 	return type == PLANET_SURFACE;
 }
 
+bool Situation::OnTile() const noexcept {
+	glm::ivec2 t(planet->SurfacePosition(surface, state.pos));
+	return type == PLANET_SURFACE
+		&& t.x >= 0 && t.x < planet->SideLength()
+		&& t.y >= 0 && t.y < planet->SideLength();
+}
+
+glm::ivec2 Situation::SurfacePosition() const noexcept {
+	return planet->SurfacePosition(surface, state.pos);
+}
+
 world::Tile &Situation::GetTile() const noexcept {
-	double side_length = planet->SideLength();
-	double offset = side_length * 0.5;
-	double x = std::max(0.0, std::min(side_length, position.x + offset));
-	double y = std::max(0.0, std::min(side_length, position.y + offset));
-	return planet->TileAt(surface, int(x), int(y));
+	glm::ivec2 t(planet->SurfacePosition(surface, state.pos));
+	return planet->TileAt(surface, t.x, t.y);
 }
 
 const world::TileType &Situation::GetTileType() const noexcept {
-	return planet->GetSimulation().TileTypes()[GetTile().type];
+	glm::ivec2 t(planet->SurfacePosition(surface, state.pos));
+	return planet->TypeAt(surface, t.x, t.y);
 }
 
 void Situation::Move(const glm::dvec3 &dp) noexcept {
-	position += dp;
+	state.pos += dp;
+	EnforceConstraints(state);
+}
+
+void Situation::Accelerate(const glm::dvec3 &dv) noexcept {
+	state.vel += dv;
+	EnforceConstraints(state);
+}
+
+void Situation::EnforceConstraints(State &s) noexcept {
 	if (OnSurface()) {
-		// enforce ground constraint
 		if (Surface() < 3) {
-			position[(Surface() + 2) % 3] = std::max(0.0, position[(Surface() + 2) % 3]);
+			if (s.pos[(Surface() + 2) % 3] < GetPlanet().Radius()) {
+				s.pos[(Surface() + 2) % 3] = GetPlanet().Radius();
+				s.vel[(Surface() + 2) % 3] = std::max(0.0, s.vel[(Surface() + 2) % 3]);
+			}
 		} else {
-			position[(Surface() + 2) % 3] = std::min(0.0, position[(Surface() + 2) % 3]);
+			if (s.pos[(Surface() + 2) % 3] > -GetPlanet().Radius()) {
+				s.pos[(Surface() + 2) % 3] = -GetPlanet().Radius();
+				s.vel[(Surface() + 2) % 3] = std::min(0.0, s.vel[(Surface() + 2) % 3]);
+			}
 		}
 	}
 }
@@ -298,52 +746,106 @@ void Situation::SetPlanetSurface(world::Planet &p, int srf, const glm::dvec3 &po
 	type = PLANET_SURFACE;
 	planet = &p;
 	surface = srf;
-	position = pos;
+	state.pos = pos;
+	EnforceConstraints(state);
 }
 
 
-Steering::Steering()
-: seek_target(0.0)
-, max_accel(1.0)
+Steering::Steering(const Creature &c)
+: c(c)
+, target(0.0)
+, haste(0.0)
+, max_force(1.0)
 , max_speed(1.0)
-, halting(false)
-, seeking(false) {
+, min_dist(0.0)
+, max_look(0.0)
+, separating(false)
+, halting(true)
+, seeking(false)
+, arriving(false) {
 }
 
 Steering::~Steering() {
 }
 
+void Steering::Separate(double min_distance, double max_lookaround) noexcept {
+	separating = true;
+	min_dist = min_distance;
+	max_look = max_lookaround;
+}
+
+void Steering::DontSeparate() noexcept {
+	separating = false;
+}
+
+void Steering::ResumeSeparate() noexcept {
+	separating = true;
+}
+
 void Steering::Halt() noexcept {
 	halting = true;
 	seeking = false;
+	arriving = false;
 }
 
-void Steering::GoTo(const glm::dvec3 &t) noexcept {
-	seek_target = t;
+void Steering::Pass(const glm::dvec3 &t) noexcept {
+	target = t;
 	halting = false;
 	seeking = true;
+	arriving = false;
+}
+
+void Steering::GoTo(const glm::dvec3 &t) noexcept {
+	target = t;
+	halting = false;
+	seeking = false;
+	arriving = true;
 }
 
-glm::dvec3 Steering::Acceleration(Creature &c) const noexcept {
-	glm::dvec3 acc(0.0);
+glm::dvec3 Steering::Force(const Situation::State &s) const noexcept {
+	double speed = max_speed * glm::clamp(max_speed * haste * haste, 0.25, 1.0);
+	double force = max_speed * glm::clamp(max_force * haste * haste, 0.5, 1.0);
+	glm::dvec3 result(0.0);
+	if (separating) {
+		// TODO: off surface situation
+		glm::dvec3 repulse(0.0);
+		const Situation &s = c.GetSituation();
+		for (auto &other : s.GetPlanet().Creatures()) {
+			if (&*other == &c) continue;
+			glm::dvec3 diff = s.Position() - other->GetSituation().Position();
+			if (length2(diff) > max_look * max_look) continue;
+			double sep = length(diff) - other->Size() * 0.707 - c.Size() * 0.707;
+			if (sep < min_dist) {
+				repulse += normalize(diff) * (1.0 - sep / min_dist);
+			}
+		}
+		SumForce(result, repulse, force);
+	}
 	if (halting) {
-		SumForce(acc, c.Velocity() * -max_accel);
+		SumForce(result, s.vel * -force, force);
 	}
 	if (seeking) {
-		glm::dvec3 diff = seek_target - c.GetSituation().Position();
+		glm::dvec3 diff = target - s.pos;
 		if (!allzero(diff)) {
-			SumForce(acc, ((normalize(diff) * max_speed) - c.Velocity()) * max_accel);
+			SumForce(result, TargetVelocity(s, (normalize(diff) * speed), force), force);
+		}
+	}
+	if (arriving) {
+		glm::dvec3 diff = target - s.pos;
+		double dist = length(diff);
+		if (!allzero(diff) && dist > std::numeric_limits<double>::epsilon()) {
+			SumForce(result, TargetVelocity(s, diff * std::min(dist * force, speed) / dist, force), force);
 		}
 	}
-	return acc;
+	return result;
 }
 
-bool Steering::SumForce(glm::dvec3 &out, const glm::dvec3 &in) const noexcept {
+bool Steering::SumForce(glm::dvec3 &out, const glm::dvec3 &in, double max) const noexcept {
 	if (allzero(in) || anynan(in)) {
 		return false;
 	}
 	double cur = allzero(out) ? 0.0 : length(out);
-	double rem = max_accel - cur;
+	double rem = max - cur;
 	if (rem < 0.0) {
 		return true;
 	}
@@ -359,5 +861,9 @@ bool Steering::SumForce(glm::dvec3 &out, const glm::dvec3 &in) const noexcept {
 	}
 }
 
+glm::dvec3 Steering::TargetVelocity(const Situation::State &s, const glm::dvec3 &vel, double acc) const noexcept {
+	return (vel - s.vel) * acc;
+}
+
 }
 }